The Scottish Tory leader said the spiralling demands being placed on the health service across the UK means it is at a “tipping point” and substantial extra funding needs to be found to sustain it in the longer term.

Amid intense criticism of the SNP over the latest waiting times figures in Scotland, she argued that the UK Government had to find more money or risk public faith in Britain’s “social contract” completely collapsing.

Ms Davidson praised the Tories’ record of cutting income tax bills, by increasing the personal allowance and higher rate tax threshold, but argued that health spending must be prioritised in future if there is a choice between the two.

One in four patients missed the 12-week treatment time targetCredit:
PA

Theresa May is expected to mark the milestone after announcing extra funding, She is understood to support the view that people would accept tax rises for the NHS if the money was used wisely.

Although health is devolved, the Barnett formula means any extra spending by Tory ministers on the English health service would result in more money being allocated to the SNP government in Edinburgh.

Official figures published on Tuesday showed a record one in four Scottish NHS patients waited longer for treatment than the 12-week guarantee enshrined in law by the SNP.

The statistics disclosed that nearly 17,000 patients due to receive planned inpatient or day case treatment waited longer than the Scottish Government target in the first three months of the year, the biggest breach of the standard since it was introduced in 2012.

But opposition parties said the guarantee was “not worth the paper it was written on” and described the SNP’s stewardship of the NHS as “shambolic”.

Cancer Research UK criticised figures showing that around one in five patients are forced to wait longer than six weeks for a diagnostic test. As of the end of March this year, more than 17,000 people were waiting longer.

Shona Robison blamed the Beast from the EastCredit:
Corbis

Ms Davidson warned of the burdens being imposed on the NHS by an ageing population, new drugs and technology. She cited the Darzi review, which concluded last month that the English NHS needs £50 billion more by 2030.

Referring to its 70th anniversary, the Scottish Tory leader said she supports finding “substantial extra funding across the whole of the UK” to put the NHS on a “solid footing for the long term”.

Addressing how she thinks the money should be found, Ms Davidson said the UK Government had “honoured its promise” to reduce the tax burden on working families.

She said: “Raising the income tax threshold has reduced taxes for millions of UK workers and has taken thousands out of taxation altogether. But the UK Government has a choice to make.

“And, if that choice is between extra spending on the NHS or introducing further tax breaks beyond those already promised, I choose the NHS.”

The Tories have pledged to raise the income tax personal allowance to £12,000 and the higher rate threshold to £50,000 by April 2020. The latter promise does not apply in Scotland as this is now set by SNP ministers.

Gillian Martin, an SNP MSP, said: “Ruth Davidson ironically makes a very strong case for how the UK is simply not working for Scotland – whether it comes to their damaging approach to Brexit, immigration, or austerity, the UK Government are actively harming jobs, public services and living standards in Scotland.”

Her speech came as official figures showed only 75.9 per cent of patients were seen within the SNP’s treatment time guarantee in the first three months of the year. This proportion dropped to just 56 per cent in NHS Forth Valley.

Ms Robison said: “This period covered a challenging winter for the NHS and severe weather in early March which caused disruption that took hospitals time to recover from.

“So it is testament to the hard work and dedication of staff that the average wait for patients receiving treatment within the treatment time guarantee was eight weeks.”

But Labour argued that the Beast from the East lasted a matter of days, starting on February 26, with forecasters stating that conditions were easing by March 2. The party noted that the treatment time guarantee has now been broken 134,804 times.

Anas Sarwar, the party’s health spokesman, said: “No one will buy Shona Robision’s attempts to hide behind a week of extreme weather to explain poor performance for three months.”

Gregor McNie, Cancer Research UK’s head of external affairs, said it was “concerning that so many people are waiting too long for tests that might tell someone if they have cancer” and blamed diagnostic staff shortages.